When a user connects hardware such as a wireless local area network (WLAN) adapter additionally to a personal computer (hereinafter referred to as PC), the user must insert a CD-ROM, one of accessories to the hardware, into a CD-ROM drive of the PC for installing a device driver and software for setting the hardware. The software installation by using the CD-ROM is a cumbersome work for the user, and if the PC has no CD-ROM drive, a CD-ROM drive should be added externally. Solutions to these problems are disclosed in, e.g. Patent Literature 1 and Patent Literature 2.
Patent Literature 1 discloses this: A WLAN adaptor has a function of being detected as a keyboard by a PC, and this WLAN adaptor is connected to a USB terminal of the PC, so that any file in the adapter can be loaded to and executed by the PC. Then the function as a keyboard is changed to a function as a WLAN adapter, so that the adapter can be used as a normal WLAN adapter.
Patent Literature 2 discloses this: A WLAN adapter is equipped with a switch that can switch between a memory device and the WLAN adapter, and the switch is set, at the first place, on the memory device side so that the PC can recognize the adapter as the memory device. Next, a driver software is loaded into the PC by an auto-run program. Then the switch is set on the adapter side so that the WLAN adapter can work as a normal WLAN adapter.
The foregoing patent literatures disclose a USB WLAN adapter to be recognized as another device by a PC for loading driver software stored in the adapter to the PC, or a USB WLAN adapter has the PC run the software automatically for setting a wireless LAN, then the user can use the adapter as a normal WLAN adapter.
However, in a case where another software, which sets a WLAN, has been installed in the PC, the setting is unintentionally and automatically switched, so that an established communication can be sometimes abruptly discontinued. Security software installed in the PC monitors data to be transmitted to the WLAN adapter, so that this security software sometimes blocks the data transmitted/received through WLAN. As a result, a normal communication cannot be expected. For instance, when the security software blocks the data transmitted from the PC to an LCD projector coupled to the PC via WLAN, the communication is interrupted, whereby a video display is unexpectedly discontinued. To avoid such inconvenience, the user should halt the function of the security software temporarily depending on an application of the PC. This is a cumbersome work for the user.
Patent Literature 1: Unexamined Japanese Patent Application Publication Number 2005-284953
Patent Literature 2: Unexamined Japanese Patent Application Publication Number 2005-341315